Despite many promising leads, new treatments for Alzheimer's are slow to emerge.
By Mayo Clinic Staff

Alzheimer's treatments currently work by temporarily improving symptoms of memory loss and problems with thinking and reasoning.

These Alzheimer's treatments boost performance of chemicals in the brain that carry information from one brain cell to another. However, these treatments don't stop the underlying decline and death of brain cells. As more cells die, Alzheimer's continues to progress.

Experts are cautiously hopeful about developing Alzheimer's treatments that can stop or significantly delay the progression of Alzheimer's. A growing understanding of how the disease disrupts the brain has led to potential Alzheimer's treatments that short-circuit fundamental disease processes.

Future Alzheimer's treatments may focus on combinations of medications like those used for many cancers and AIDS rather than a single compound. The following treatment options are among the strategies currently being studied.

Some of the new Alzheimer's treatments in development target microscopic clumps of the protein beta-amyloid (plaques). Plaques have long been considered a sign of Alzheimer's disease.

Two strategies aimed at beta-amyloid include immunizing the body against it and blocking its production:

Immunization strategies may prevent beta-amyloid from clumping into plaques and help the body clear the beta-amyloid from the brain. An early Alzheimer's vaccine to reach clinical trials mobilized a person's own immune system to attack beta-amyloid.

Researchers stopped this study ahead of time when some participants developed acute brain inflammation. Although the trial ended before researchers could fully assess the vaccine's effectiveness, the study demonstrated that beta-amyloid immunization could have a powerful effect on the brain.

Most current immunization studies focus on administering antibodies against beta-amyloid from outside sources instead of enhancing a person's immune system.

One large research effort is exploring the value of intravenous (IV) infusions of a product derived from donated blood. This product contains naturally occurring anti-amyloid antibodies from the donors. Other studies are investigating laboratory-engineered (monoclonal) antibodies.

Production blockers may reduce the amount of beta-amyloid formed in the brain. Research has shown that beta-amyloid is produced from a "parent protein" in two steps performed by two different enzymes. Several experimental drugs aim to block the activity of the two enzymes.

A vital brain cell transport system collapses when a protein called tau twists into microscopic fibers called tangles, which are another common brain abnormality of Alzheimer's. Researchers are looking at a way to prevent tau from forming tangles.

Studies in nonsteroidal anti-inflammatory drugs have had varying results, but haven't confirmed that these drugs prevent or delay progress of Alzheimer's.

Researchers are studying the effects of insulin on the brain and brain cell function, and insulin changes in the brain that may be related to Alzheimer's. A trial is testing an insulin nasal spray to determine if it slows the progression of Alzheimer's.

Growing evidence suggests that brain health is closely linked to heart and blood vessel health. Your arteries nourish your brain. The risk of developing Alzheimer's appears to increase as a result of many conditions that damage the heart or arteries. These include high blood pressure, heart disease, stroke, diabetes and high cholesterol.

In addition, a strong genetic Alzheimer's risk factor is one form of a gene for a protein that carries cholesterol in the blood (apolipoprotein E).

A number of studies are exploring how best to build on this heart-head connection. Strategies under investigation include:

Current drugs for heart disease risk factors. Researchers are investigating whether drugs now used to treat high blood pressure, diabetes and high cholesterol may also help people with Alzheimer's or reduce the risk of developing the disease.

Drugs aimed at new targets. Additional projects are looking more closely at how the connection between heart disease and Alzheimer's works at the molecular level to find new drug targets.

Lifestyle choices. Researchers have explored whether lifestyle choices with known heart benefits, such as exercising on most days and eating a heart-healthy diet, may help prevent Alzheimer's disease or delay its onset.

Studies research whether thinking (cognitive) activities, such as memory training, may help prevent or delay Alzheimer's.

Researchers also are studying whether social interaction may positively affect cognitive function.

Developing new medications is a slow and painstaking process. The pace can be especially frustrating for people with Alzheimer's and their families who are waiting for new treatment options.

To help accelerate discovery, the Coalition Against Major Diseases (CAMD), an alliance of pharmaceutical companies, nonprofit foundations and government advisers, have forged a first-of-its-kind partnership to share data from Alzheimer's clinical trials.

Researchers anticipate that sharing these data from more than 4,000 study participants will speed development of more-effective therapies.

Reprint Permissions

A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.